In recent years the popularity of endoscopic surgery has proliferated. This has occurred because of the advances in technology which allow smaller and smaller endoscopes to be used, thereby permitting operative procedures to be undertaken in a less invasive manner than was previously possible. Thus, the patient suffers less trauma, recuperates much more rapidly and experiences less pain and discomfort than with more conventional surgical procedures.
Because of the sophisticated optics and electro-optics contained in modern endoscopes, they generally are very expensive. In order for this expense to be justified, they must be reused with a large number of patients.
Of course, reuse requires that the endoscope must be sterilized or at least disinfected after use with each patient prior to use with the next patient. One protocol for sterilization involves immersing the endoscope in a disinfectant solution for a predetermined period of time. It is also important to flush the channels inside the endoscope which carry gases, fluids, or which receive operative instruments. When using the disinfectant, sometimes the endoscope is not placed in the disinfecting solution for a sufficient length of time nor are the channels flushed out completely because of the urgency to get the endoscope back into service as soon as possible. Over time, the disinfectant solution may lose some of its strength, thereby limiting its effectiveness. Another protocol is to heat sterilize the endoscope by placing it in an autoclave. However, the optics and electronics of many endoscopes will not permit them to be subjected to heat sterilization.
Because of these shortcomings, studies have shown that transmission of infectious diseases from one patient to another has occurred in many instances. By way of example, transmission of salmonella typhi has been reported. In addition, pseudomonas aeruginosa has been linked to endoscopy. Also, an outbreak of serratia marcescens has been associated with the use of a bronchoscope. Furthermore, Hepatitis B has been transmitted by endoscopes when the endoscopes were processed in an inappropriate manner between patients. Finally, with respect to endoscope use on patients with acquired immune deficiency syndrome (AIDS), it has been found that the sterilizing procedures have not always removed contamination of the human immunodeficiency virus (HIV). This list is not exhaustive by any means.
A high-level of disinfection failures among gastrointestinal endoscopes have been noted, as well as failures in bronchoscopes, laryngoscopes and other devices. This may be due to the fact that they are long and narrow and have internal channels that are difficult to sterilize.
Another shortcoming of the prior art is that when a tube assembly is attached to the distal end of an endoscope not having integrally formed internal passageways, the resulting cross-sectional shape was greatly increased because the tube assembly was not structurally designed to mate with the endoscope. A larger cross-sectional shape results in increased trauma to patients undergoing surgery.
From the foregoing, it is apparent that endoscopes are needed that can be more easily and effectively sterilized, and that maintain a small size to accommodate minimal invasive surgery.